The present invention relates to a curing composition for the fast curing of coating compositions containing acrylic polyols.
In the coating of automobiles, for example, a coating is desired that provides a lustrous appearance and has good corrosion resistance. Such coatings are usually applied in several coating layers with typically a pigmented base coating composition applied followed by a clear topcoat. In some instances, the topcoat may contain pigments which provide a color to the topcoat, or a single pigmented coating composition may be used. Acrylic polyol based coating compositions are particularly useful for these applications. Especially desirable are acrylic polyol based clear coating compositions which can be used as "universal" clear coats over a variety of basecoats to provide a hard, durable finish.
Although such acrylic polyol based coating compositions have excellent properties as automotive coatings, both on metal and plastic substrates, the length of time required for curing can be a drawback. The curing time for such coatings is labor sensitive and a fast cure of the coating is preferred, while at the same time maintaining a useful gel time, i.e. the coating composition should not gel when being used until sufficient time has lapsed for spraying or otherwise applying the coating composition. Typically, a gel time of about one hour is desired to allow sufficient time for application.
Accordingly, acrylic polyol based coating compositions are desirable that will provide not only a suitable gel time but also a rapid cure.